How high should your blood pressure raise after exercise-in terms of systolic and diastolic values? E.g is 127/74 before and 150/101 a normal increase after walking up and down a 16 inch step?

BP and excercise. It is normal for your blood pressure to increase during and right after exercising. If that is the reading about 20 minutes after resting, you should be concerned. Check with a local physician if that is the case. Otherwise, you should keep doing what you do. Exercise and eat healthy.
No established rule. The numbers you mentioned are fine. We don't really look at the blood pressure response immediately after exercise, since they vary widely based on whether you're doing aerobic or isometric exercises. So as long as your blood pressure is normal at rest, then you're fine. Maintaining a healthy diet and doing regular exercise is the best way to keep your blood pressure within normal range.